Role of the GABAergic system in nicotine addiction: Reward and physical dependence in mice

MOUTINHO L.; BALERIO G.

Tandil, Argentina

Congreso; Asociación Argentina de Farmacología Experimental. XL Reunión Anual de Comunicaciones Científicas; 2008

Asociación Argentina de Farmacología Experimental

ROLE OF THE GABAERGIC SYSTEM IN NICOTINE ADDICTION: REWARD AND  PHYSICAL DEPENDENCE IN MICE Moutinho L 1 and Balerio G1,2 1ININFA (CONICET), 2 Cát. de Farmacología, FFYB (UBA). Junín  956  5°Piso (1113), Bs. As. E-mail: gbalerio@ffyb.uba.ar Repeated nicotine administration in animals produces several behavioural responses related to its addictive properties, such as reinforcing effects and physical dependence. The aim of the present study was to examine the possible role of the GABAergic system in NIC-induced rewarding effects using the conditioned place preference paradigm (CPP) and in the somatic expression of NIC abstinence. The CPP protocol was performed in three phases. Pre conditioning: (Day 1), mice were tested to determine time spent in each compartment for 18 min. Conditioning: (Day 2), animals were pretreated with BAC (2 mg/kg, i.p.) or saline injection and immediately confined to one of the choice compartments for 20 min. Six hours later, mice were injected with the alternate condition and confined to the opposite choice chamber. This procedure was repeated on days 3-4-5. Post conditioning: (Day 5) the procedure was identical to Day 1. A model of naloxone (3 mg/kg, sc) (NAL)-induced abstinence in chronic NIC-treated mice (25 mg/kg/day, sc) was developed using implanted osmotic minipumps. NIC produced rewarding effects (p<0.01) while BAC did not significantly modify these effects. NAL precipitated NIC withdrawal (p<0.001) and BAC attenuated the severity of this withdrawal (p<0.001). These results demonstrated that the somatic expression, but not the reinforcing motivational effects can be modulated by the endogenous GABAergic system. Supported by UBACYT B021 and B016           Presentación: POSTER.